STOL aircraft

ABSTRACT

An electrically powered STOL aircraft having dedicated motors energized to deploy movable landing gear driven to propel short takeoffs and to actively rotate downwardly to engage the runway surface as the aircraft approaches touchdown on landing. The front and rear landing gear, or both, may be powered and actuated in the landing process with braking to shorten the landing distance, each driven landing gear wheel having a dedicated electric motor and coaxial brake.

BACKGROUND OF THE INVENTION Technical Field

The present invention relates most generally to fixed wing aircraft, andmore particularly to an electrically powered fixed wing aircraft, andstill more particularly to an STOL electric aircraft suitable forextremely short field takeoffs and landings in an urban environment.

Background Art

Visit any large urban area today and you almost immediately experiencetransportation problems. Short rides using surface transportation (bus,car, taxi) can take longer than walking the same route and distance at aleisurely pace. Subways and trains are overcrowded and correspondinglyunpleasant. Population growth and urban migration models and predictionsmake clear that the problems will only get worse.

In consequence, there is considerable activity to devise transportationalternatives that reduce the load on existing systems. One approachtakes advantage of the almost entirely untapped urban space above us—thesky above streets and buildings.

Current work and research is principally being conducted at a freneticpace by tech, peer-to-peer ride-sharing, and aircraft companies, todevise and design aircraft suitable for use in an urban “air taxi”system. Airbus, Boeing, Google, Pipistrel, NASA, and others have throwntheir hats into the ring. Without exception, their early and prototypedesigns derive from existing vertical takeoff and landing (VTOL) droneand helicopter designs, including tilt wing, ducted fan, helicopters,cyclogyros, tiltrotors, and so forth. The express intention is that theaircraft be able to utilize building tops as skyports. Highly layeredurban traffic control areas for such use are also contemplated.

We may see the realization of a fully functional urban air mobilitysystem within a decade. New, high-powered electric motors and powermanagement controllers for aviation are available. New air trafficmanagement hardware and artificial intelligence systems to controlindividual aircraft and provide safe separation from other aircraft inthe system are being studied. Pilotless and Optionally Piloted Aircraft(OPA) and other types of autonomous aviation controls are also beingdeveloped. However, proposed aircraft designs for use in urbanenvironments are, without exception, of the VTOL type.

Unfortunately, VTOL aircraft known to date, including electric aircraft,have numerous disadvantages, most notably in creating high noise andconsuming significant energy on takeoff and landing. Accordingly, it maybe desirable to provide a more conventional aircraft to achieve the sameobjectives of VTOL design for an air taxi or urban air mobility system.

An alternative to VTOL aircraft are short takeoff and landing (STOL)aircraft. These aircraft are common; their primary advantage overconventional aircraft is that they are able to operate from shortrunways. They have been widely used for military transport since the1950s and as “bush” planes in remote wilderness areas. The shortcomingof STOL aircraft is that the landings are generally ill-adapted forurban environments.

What is needed, therefore, is an improved STOL aircraft capable of quietand energy efficient operation in an urban environment, usingbuilding-top runways of reasonably short length.

DISCLOSURE OF INVENTION

The aircraft of the present invention includes a novel type of landinggear that makes it possible for the aircraft to achieve short takeoffsand smooth, short landings in approximately 60 meters or less. Theapplication for the inventive aircraft and its advanced landing gear isfor an all-electric STOL plane capable of high cruise speeds (up to 400km/hr) (250 mph) in nearly all weather conditions.

Acceleration and deceleration are expressed in units of g-force, or “g”.The derivative of acceleration with respect to time (or the change inthe rate of acceleration/deceleration) is known as “jerk”, and it ismeasured in g/sec.

Most individuals easily tolerate acceleration/deceleration rates over 2g without alarm or discomfort if the rate is gradual, smooth, anduninterrupted. A commercial airliner landing has fairly low decelerationbut high jerk rates. Jolts and bumps even at a low 0.5 g feel jarringand alarming for some people.

To accommodate a wide range of individual comfort levels, takeoffs andlandings must be reassuringly smooth and free of whiplash, jolts,let-ups, shakes, and bumps. A straightforward and effective way toachieve short distance takeoffs is by simply accelerating, or drivingthe plane to takeoff speed. The inventive aircraft employs a drivenwheel that is positioned far aft of the center of gravity (COG) toprevent tip back. However, because the drive wheel is back from the COG,the plane rotates less easily at takeoff. To balance the desiredperformance characteristics, rotation is forced at the end of thetakeoff run using motorized front landing gear that effectively drivesthe nose up at takeoff. The same motorized mechanism is used to softenthe landings.

STOL landings are also challenging. The landing distance must not onlybe short, but the plane must consistently hit a very narrow touchdownmark, all while coming in fast and decelerating hard in choppyconditions. Even with advanced robotic controls, this cannot be achievedwhile following a smooth, jolt-free path. How, then, is it done?

The inventive aircraft includes sensors that envelope the plane andprecisely measure the distance to the ground as the plane passes intothe touchdown zone. When the plane passes over the touchdown zone within±0.5 meters (20 in) of a target height, motorized landing gear israpidly deployed and closes the distance between the plane and theground. The wheels touchdown solidly, but do not bounce the plane. Thefront landing gear touches well ahead of the COG, and the entire weightof the plane is immediately shifted off the wing and onto the wheelswithout any concern for nosing over during hard braking. The frontwheels disposed on the outer ends of the landing gear struts take overto decelerate the plane and the legs gently lower the body of the planeto a resting position.

Other novel features which are characteristic of the invention, as toorganization and method of operation, together with further objects andadvantages thereof, will be better understood from the followingdescription considered in connection with the accompanying drawing, inwhich preferred embodiments of the invention are illustrated by way ofexample. It is to be expressly understood, however, that the drawing isfor illustration and description only and is not intended as adefinition of the limits of the invention. The various features ofnovelty which characterize the invention are pointed out withparticularity in the claims annexed to, and forming part of, thisdisclosure. The invention resides not in any one of these features takenalone, but rather in the particular combination of all of its structuresfor the functions specified.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and objects other than those setforth above will become apparent when consideration is given to thefollowing detailed description thereof. Such description makes referenceto the annexed drawings wherein:

FIG. 1 is an upper front perspective view showing the STOL aircraft ofthe present invention in flight with two occupants;

FIG. 2 is a schematic cross-sectional left side view in elevation takenalong section line 2-2 of FIG. 1, this view not including the aftportion of the frame member and empennage;

FIG. 3 is a detailed cross-sectional left side view in elevation showinga portion of the forward landing gear drive mechanism as taken alongsection line 3-3 of FIG. 2;

FIG. 4 is an upper front right perspective view showing both arms of theforward landing gear and drive forward landing gear drive;

FIG. 5 is an upper front left perspective view showing the aircraft in ataxi configuration;

FIG. 6 is a side view in elevation of the aircraft in a landingconfiguration as the plane nears the landing zone, showing forwardlanding gear at a position nearing maximum downward deployment justbefore ground contact is made;

FIG. 7 is a left side view in elevation illustrating the operation andconfiguration of the forward landing gear and rear landing gear midwaythrough the landing sequence;

FIG. 8 is a left side view in elevation showing the landing gear in ataxi configuration as well as pre-rotation takeoff configuration;

FIG. 9 is a left side view in elevation illustrating the operation offorward landing gear driving the aircraft nose up during rotation attakeoff;

FIG. 10 is a left side view in elevation showing alternative landinggear structure in the pre-touchdown configuration during landing withthe front and rear landing gear in the maximum downward deployment;

FIG. 11 is a side view in elevation thereof illustrating the operationand configuration of the forward landing gear and rear landing gearmidway through the landing sequence;

FIG. 12 is a left side view in elevation thereof showing the landinggear in a taxi configuration as well as pre-rotation takeoffconfiguration;

FIG. 13 is a left side view in elevation thereof illustrating theoperation of forward landing gear driving the aircraft nose up duringrotation at takeoff;

FIG. 14 is a schematic partial cross-sectional left side view inelevation taken along the longitudinal midline of the plane and showingthe aircraft in flight, the aft portion of the plane and empennageexcluded from the view;

FIG. 15 is an upper front left perspective view of the front and rearlanding gears in a fully retracted and stowed configuration;

FIG. 16 is an upper left perspective view showing the structural andoperational elements of the front and rear landing gear;

FIG. 17 is a rear left side perspective view showing a takeoff sequencefor the landing gear of the present invention;

FIG. 18 is a flowchart showing the conditions monitored and the actionstaken by the aircraft control systems during the takeoff sequence;

FIG. 19 is a front left side perspective view showing the landingsequence for the landing gear of the present invention; and

FIG. 20 is a flowchart showing the conditions monitored and the actionstaken by the aircraft control systems during the landing sequence.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring first to FIGS. 1 through 15, wherein like reference numeralsrefer to like components in the various views, there is illustratedtherein a new and improved STOL Aircraft, generally denominated 100herein.

Preferred embodiments of the aircraft 100 achieve short takeoffs andlandings whether piloted or unpiloted, as in remotely controlled droneflight. In the preferred embodiments having the shortest takeoff andlanding distance, the avionic systems control critical landing gearmovements and the overall landing gear configuration to coordinate gearpositions with one or more of the following conditions, includingheight, airspeed, ground speed, and runway position.

In accordance with the present invention the STOL aircraft 100 comprisesa central fuselage 110 that supports left and right wings 120 and 120′.Empennage (tail wing assembly) 190 includes elevators 191. The empennagemay be any of a high-wing, low-wing, or mid-wing design.

Fuselage 110 in preferred embodiments deploys a globular cockpit 115 andcan provide or be extended to provide a cargo bay. The fuselage includesan axially disposed aft frame member 111 that supports the tail assemblyat the distal end 111 b, with the proximal end 111 a joined at thecommon wing junction above the globular cockpit.

In preferred embodiments the front landing gear 150 is deployed in thelanding process to absorb energy, and both the front and rear landinggear configurations and operation enable short takeoff distances.

The front landing gear 150 preferably comprises a pair of struts151/151′ on opposing right and left sides of the fuselage 110, each withthe drive mechanism shown in FIG. 3.

The preferred modes of takeoff and landing are further enabled by theconfiguration of the fuselage and other heavy components that positionthe center of gravity (COG) between the front and rear landing gear.

The two front landing gear struts 151, 151′ and the rear landing gearstrut 156 are each driven by a separate motor, preferably electric.

Front landing gear 150 and rear landing gear 155 are connected to theglobular cockpit 115. As shown in FIGS. 1 and 4-5, the front landinggear 150 includes a pair of linear struts 151/151′ coupled to thefuselage or cockpit 115 by a rotary joint 152 at a proximal end with thedistal end supporting at least one wheel 161/161′ in rotary engagement.

The rear landing gear 155 deploys a linear strut 156 and includes awheel 162 at a distal end, and a pivotal connection to the fuselage 110or cockpit 115 using a rotary joint or coupling 157. Wheel 162 is drivenby an in-line motor (not shown) to accelerate the aircraft for takeoff.It is preferably operatively coordinated with the movement of the frontlanding gear 150 by a Ground-Air-Made-Short (GAMS) landing gear 1500.

Successful short runway landings require that the aircraft wheels touchdown in a narrow range in the landing zone. The requirements may be onthe order of a tenth of a second for the minimum potential runwaylength. The means to achieve such exactitude is to have the landing gear“reach” for the ground at the exact moment needed, which means that thelanding gear is actively rotated downwardly in relation to landingconditions data relating to height over the runway, position in thelanding zone, ground speed, vertical speed, and so forth. As theaircraft nears the runway, the avionics control system rotates thelanding gear down to engage the ground before the gear would otherwisecontact the ground on a glide path for decelerating the plane.

The other part of the solution is to eliminate wing loading and transferweight onto the landing gear to maintain high deceleration through wheelbraking. As speed drops, high deceleration is difficult to achieveaerodynamically. It is a key requirement, therefore, to initiate andproduce as much forward horizontal deceleration in the air and maintainthat deceleration during landing.

The GAMS landing gear 1500 employs a motor 1520 to position the frontlanding gear 150 and rear landing gear 155. The same assembly includes adisc brake 1530 to dissipate the vertical sink energy. The elongate andrelatively long landing arms or struts 151/151′ and 156 are dimensionedto accommodate a wide variety of approach conditions and to ensure thatthe aircraft does not bounce or porpoise on touchdown and rollout.

The front landing gear 150 deploys the wheel supporting struts 151downwardly when they are in a range of distance from the ground thatthey will touch the ground as they descend. The contact is sensed sothat the wings can then be actively and rapidly unloaded of lift (using,for instance, spoilers), so vertical deceleration is absorbed by theforward landing gear brakes as well as the wheel brakes that absorbhorizontal deceleration.

A long wheelbase (the distance between front wheels 161 and rear wheel162) when the gear is deployed may be advantageous for acceleration ontakeoff, but it is disadvantageous for rotation on takeoff. Wheeledvehicle acceleration and deceleration requires a long wheelbase with thecenter of gravity near the midline. The need for easy and quickembarkation introduces further challenges. An aircraft with a longwheelbase cannot take off without powered assistance. Thus, the sameGAMS power unit is employed to force the aircraft to rotate for takeoff.

In a preferred embodiment, a plurality of electric motors provide landand flight propulsion.

In another preferred embodiment, at least one landing gear wheel drivesthe plane on the ground to the lift off speed. The strut portion of thegear is then driven to provide upward thrust at lift off. The upwardthrust from the landing gear adds to the lift provided by wings. TheGAMS mechanism of FIG. 3 is the preferred mechanism to provide thisfunction.

The preferred embodiments of the aircraft 100 are expected to have arunway length requirement of 60 meters or less.

The GAMS power unit 1500 is illustrated in detail in FIG. 3, in which amotor 1520 supported on a yoke 1510 has a shaft 1540 that is supportedby a ball screw joint 1550. The rear landing gear strut is configured asa form 1 lever having a rotary joint coupling as the fulcrum. The end ofthe shaft 1540 a is rapidly urged (in the direction of arrow 102)against the arm 1571 of the rear wheel strut 156, rotating the strut andforcing the wheel 162 downward. The motor 1520 rotation is stopped bythe disc brake 1530.

On landing, shaft 1540 moves in the reverse direction, counter rotatingthe motor to absorb the energy of landing as the strut 156 movesupwardly, with the energy also absorbed by the disc brake 1530. Landingenergy can also be absorbed by one or more conventional shock absorbers,such as various forms of springs, as well as active suspension systemsthat may deploy electromagnetic actuators, as well as combinationsthereof. Such energy absorbing systems can have any combination oflinear and non-linear energy absorption.

The GAMS power unit also operates to lift and deploy the forward wheels161/161′ by rotating struts 151/151′. The forward wheel struts 151/151′each have a lateral shaft 153/153′ coupling to rotate as the hingedcoupling 1560 is rotated by the ball screw actuator arm 1580 thatcouples in turn to the ball joint 1550 that receives the threaded shaft1540 connecting to the motor 1520. Other motors drive the propellers,landing gear, control surfaces, and wheels for ground propulsion, andare powered by a modular battery 140 capable of fast interchange forquick turnaround.

An energy or power source 140 provides energy to power the motors135/135′. One or more primary motors which drive one or more propellers130/130′, which may be two motors 135 and 135′ mounted on the left 120and right 120′ wings. A modular battery 140 is a preferred power source.The modular battery 140 may be mounted to the fuselage 110 or aircraftso that it can be jettisoned rapidly in the event of fire or any otherimpending hazardous state or condition. The power source 140 can be asort of solid state battery as well as a fuel cell and a source ofhydrogen for the fuel cell. Alternatively, the power source can beliquid fuel that drives an internal combustion motor, which in turngenerates electricity by driving an electric dynamo-machine, i.e., agenerator.

It should also be appreciated that it is preferable that the COG isdisposed between the front landing gear 150 and rear landing gear 155 bythe central placement of the passenger seats and the power supply.

The battery is preferably supported by translating it longitudinallywithin the airframe to adjust the COG with respect to the load frompassengers or freight. Placement of battery, cargo containment means(and other heavy components) within the fuselage 110 and cockpit 115properly positions the COG.

An optional cargo bay is preferably a module that forms part of theouter skin on the fuselage behind the cockpit.

Looking next at FIG. 15 there is shown the front landing gear and rearlanding gear modules, each isolated and physically removed from theairframe and shown in a fully retracted configuration, as they appearwhen the aircraft is in midflight cruise operation.

Referring now to FIG. 16, details of an embodiment of the landing gearstructures and operational drive systems are shown. Reference numbersfrom the earlier views for like elements are not carried over here;instead new reference numbers are provided for similar earlieridentified structures as well as for newly identified detail features.

FIG. 16 illustrates that in an embodiment the front and rear landinggear assemblies structurally connect to, and operate in relation to, theaircraft airframe 200 so as to form a system suited for STOL operations.The airframe 200 (for convenience arbitrarily shown here as a section ofindeterminate size) supports and connects to a front landing gear module250 and a rear landing gear module 350. The airframe includes aninterior surface or side 202, a longitudinally-oriented center slot 204,and left and right (port and starboard) sockets 206, 208, respectively.The front landing gear module 250 is operatively and pivotally connectedto the airframe and its interior side 202 through the port and starboardsockets 206, 208.

The front landing gear module includes port and starboard struts or legs252, 254, respectively. Each leg includes, at a distal end, a fetlock256, 258, pivotally connected to the leg at a fetlock pivot 260, 262; afront cradle 264, 266 (latter not showing) pivotally coupled to thefetlock at a cradle pivot 268, 270 (latter not shown); a cowling 272,274 pivotally connected to the front cradle at a cowling pivot 276, 278;and terminating in driven wheels 280, 282, rotatingly disposed on axles284, 286 (port side not visible). Drive systems/motors 288, 290 areprovided for each wheel (again, port side not visible). Clamshell doors292, 294 may be provided to enclose the wheels in flight.

Each front landing gear strut 252, 254 (port and starboard) terminatesas an inboard rotatable deployment/retraction axle 300, 302, each axledisposed through an airframe socket, port and starboard, 206, 208,respectively. Each axle is driven by a lead screw 304, 306 pivotallyconnected to the axle with a pintle/gudgeon coupling 308, 310. Thecoupling and axle form bell cranks 312, 314.

Electric motors 316, 318 are mounted to the airframe interior side 202with a trunnion/bracket mount 320, 322, which extend their respectivelead screws to retract the corresponding strut or retract theirrespective lead screws to deploy or extend the respective strut. Motortrunnions pivot at pivot points 324, 326 (latter not clearly visible).Motor control for both the deployment/retraction of the landing gearstruts and for their respective drive wheels resides in system avionicsdescribed more fully below.

In the embodiment shown in FIG. 16, the rear landing gear module 350includes a rear leg strut 352 having a driven rear wheel 354 rotatinglycoupled to the strut through an assembly that includes an axle 356disposed through a rear wheel fork 358. A rear wheel drive system 360 isoperatively coupled to the rear wheel. The rear wheel fork 358 ispivotally coupled to a rear wheel gimbal 362 through a fork/gimbal pivot364. In turn, the gimbal 364 is pivotally coupled to the rear strut 352through a gimbal/strut pivot 366. A rear wheel fairing 368 partiallyencloses the rear wheel, the enclosure selectively completed by a tailfairing door 368 a.

The rear landing gear, like the front landing gear, is driven by a strutdrive system, 370, which in embodiments is an electric motor. It ismounted on the airframe inner side with a motor trunnion 372 pivotallymounted on a trunnion bracket 374. The motor drives a lead screw 376that engages a rear strut clevis 378 to pivot the strut on a rear strutshaft 380 disposed in a trunnion carriage 382. Motor control againresides in avionics control systems, described more fully below.

Operation of the landing gear modules just described may be seen byreferring now to FIGS. 6-13, 17 and 19, where there is shown a range ofthe dynamically adaptive landing gear configurations during landing andtakeoff sequences.

Thus, and looking first at FIG. 17 and concurrently referring back toFIG. 9, there are shown configurations of the aircraft during a takeoffsequence. The sequence in FIG. 17 proceeds over time from right to left.In the rightmost schematic image 400 of the inventive aircraft, thelanding gear can be seen to be in a taxiing configuration 402. Bothfront and rear wheel steering are enabled and the wheels may beselectively driven, as needed. In the middle view 406, the aircraftlanding gear is in its ground roll configuration 408, similar to thetaxiing configuration except that the front landing gear has limitedsteering and the rear wheel is powered and its steering is locked. Asthe plane reaches and then exceeds a predefined landing-gear-enhancedrotation speed, 410, the landing gear control system rotates the frontlanding gear downwardly into a rotation configuration 412 to drive theaircraft nose up, increasing the angle of attack and dramatically andrapidly increasing lift. The rotation configuration 412 is shown moreclearly in FIG. 9.

Looking next at FIG. 19, and then back at FIGS. 6-9 and 11-13, there areshown a sequence of landing gear configurations corresponding to atypical landing as might be accomplished using the advantageousdynamically active landing gear of the present invention. FIG. 19 showsthe developing configurations. In a cruise flight 420 the front and rearlanding gear struts are fully retracted and folded underneath theairframe in a cruise flight configuration 422. Then as the aircraftreaches a late stage of final approach 430, the front landing gear isactivated and deployed into an approach configuration 432. This may becharacterized as a “reaching forward” configuration. Before and as thisconfiguration is achieved, flight system controls align the aircraft andplace it on an approach vector and glide slope that will enable it toland safely on the STOL runway. Then, when the aircraft passes through atarget cloud 440, both front and rear landing great struts are rapidlyextended downwardly. The target cloud referred to herein is a virtualenvelope enclosing a predetermined volume of airspace defined by a rangeof possible safe landing positions above and close to the runwaythreshold on the approach when the aircraft meets certain parameters(e.g. ground speed). In embodiments, the target cloud may be a cuboidairspace having 10×10×1 meter dimensions. When the aircraft position 442is detected as being in the target cloud, the dynamically active landinggear “reaches” down 444 toward the runway to more quickly bring thefront and rear landing gear wheels into contact with the runway. Theaircraft then rapidly slows to a roll out and taxiing configuration 446with the front landing gear struts fully extended forward and the rearlanding fully extended aft 448.

FIGS. 6-8 show configurations intermediate those of FIG. 17. FIG. 6shows the aircraft landing gear configuration as the target cloud isreached. FIG. 7 shows the landing gear as the energy of the verticalsink is absorbed by the landing gear. FIG. 8 shows the configuration asthe landing gear reaches the taxiing configuration.

FIGS. 10-12 show an alternative landing gear assembly in landing gearconfigurations corresponding in sequence to the landing gearconfigurations shown in FIGS. 6-9. Preliminarily, it should be notedthat the salient alternative features include a rear landing gear wheel162 rotatable about a pivot at the distal end of the rear landing greatstrut 156 so as to enhance the “reaching” feature during landing. Thefront landing gear wheels have a similar feature, enabling them to pivotand extend downwardly as the plane approaches the runway.

In preferred embodiments, the avionics system controls the landing geardeployment in coordination with the propeller and wheel drives for theprecise movement with respect to location and speed to fully enable theSTOL advantages. Such an avionics control system may be capable ofremote or drone control, as well as autonomous or semi-autonomouscontrol. More pertinently, the landing gear system control may be pilotcontrolled or, in a pilotless/autonomously controlled embodiment,controlled with on-board system avionics or remotely controlled from acentralized control system.

FIG. 18 shows the conditions monitored and actions taken by the controlsystems during a takeoff sequence 500. Cabin conditions, passengersafety checks, scheduling taxi and takeoff movements according toskyport/airport and area traffic, and the like are understood andassumed, and therefore not set out here. Rather, the focus is on therole played by the aircraft landing gear in facilitating a short fieldtakeoff. Mention should be made, however, that all pre-flight activitiesare handled either by system controls alone or in combination withactions by flight personnel. For instance, in preparation for flight,the aircraft doors are closed and the plane shifted from a loadingconfiguration to a taxi configuration, and the cabin and any passengersare readied for flight. The landing gear and flaps are configured forground roll 502, and plane then taxis toward the runway 504. It thenmerges onto the runway and is aligned with the runway centerline 506.Full power is applied to the propellers 508. Drive wheel power isemployed to supplement acceleration as needed 510 until rotation speedis reached 512. At that point, wings and flaps are deployed in acustomary manner according to wind conditions, aircraft loading, andavailable runway length 514. Concurrently or immediately after, thefront landing gear struts are driven downwardly so as to push theaircraft nose upward 516 to an optimal angle of attack to shift loadingonto the wings to get into and through ground effect and into freeflight at higher altitude 518. The landing gear is pulled up (wheels up)520, and the plane is then configured 522 for optimal climb performanceaccording to the climb requirements needed to clear obstacles, to remainclear of other traffic in the urban Traffic Control Area, and to achievelevel flight altitude. The landing gear is then fully retracted intocruise flight configuration 524 and the aircraft proceeds to itsdestination.

FIG. 20 shows the conditions monitored and the actions taken by theaircraft control systems as the aircraft approaches its destination andduring the landing sequence at the destination 600. When the aircraftenters an airport/skyport traffic pattern 602 its speed and flapconfiguration are adjusted 604. When cleared for landing and vectoredonto final approach, the aircraft turns to a final approach heading andis aligned with the runway centerline 606. Aircraft sensors then lockonto the landing target (the above-described target cloud) 608 and thefront landing gear is extended outwardly 610 and readied for dynamicadjustments immediately preceding touchdown. Further fine adjustmentsare made in response to air and wind conditions and aircraft flightconditions (loading, groundspeed, wind direction, current flight controlconfigurations, etc.) 612. Full flaps are deployed as needed 614.Sensors in the front landing gear struts measure the closing distance tothe target cloud 616 and when the aircraft is within a predetermineddistance, precision distance measuring sensors are engaged 618. Thesesensors search for and signal the control system when the aircraft iswithin the target cloud 620. In response, the landing gear isimmediately deployed downwardly to “reach” for the ground 622. Landinggreat struts move independently to compensate for aircraft roll or pitch624. The process continues to touchdown 626, at which time spoilers areactuated 628 and loading is shifted entirely from the wings to thelanding gear 630. Deceleration continues 632, brakes are applied 634,and vertical sink energy is absorbed and adjusted to maximize landingsmoothness and minimize jerk 636. Once a sufficiently low speed isachieved, the landing gear is moved into a taxi configuration 638. Theaircraft will quickly reach maximum deceleration 640, and it willcontinue a short roll at taxi speed 642. The flaps are retracted 644,and the plane taxis off the runway 646, ready for unloading and forpreparations for a next flight.

From the foregoing, it will be seen that in its most essential aspects,the present invention is an STOL aircraft that includes a fuselagehaving a port and a starboard side; at least one fixed wing coupled tothe fuselage and extending laterally from each of the port and thestarboard side; at least one propeller coupled to either the fuselage orthe at least one fixed wing to provide thrust; a power plant to powerthe at least one propeller; front and rear landing gear modulesoperatively coupled to the fuselage, each of the front and rear landinggear modules including at least one rotatable landing gear strut with awheel disposed on its distal end; landing gear motors for driving thefront and the rear landing gear struts independently; and a controlsystem for controlling the landing gear motors to deploy and retract thefront and rear landing gear struts; wherein the control system isprogrammed to rotate one or more of the landing gear struts in responseto aircraft flight condition and position data, including airspeed,ground speed, and position in relation to a runway.

Advantages of embodiments of the invention arise from the preferredexclusive use of electric motors for all the drive mechanisms to improvereliability and to decrease maintenance, as this eliminates fuel andhydraulic lines, which are prone to leaks and failure over time. Suchleaks can create slip hazards on airstrips and reduce an aircraft'sability to decelerate safely in a limited space.

The foregoing disclosure is sufficient to enable those with skill in therelevant art to practice the invention without undue experimentation.

While the particular aircraft herein shown and disclosed in detail isfully capable of attaining the objects and providing the advantagesstated herein, it is to be understood that it is merely illustrative ofthe presently preferred embodiment of the invention and that nolimitations are intended to the detail of construction or design hereinshown other than as defined in the appended claims. For instance, thosewith skill will appreciate that the advantageous feature of the landinggear—that of “reaching” for the runway surface close to touchdown—couldbe accomplished with alternative mechanical structures, such astelescoping landing gear struts or struts that articulate at a pointalong the length of the struts distal to the connections at thefuselage. Accordingly, the proper scope of the present invention shouldbe determined only by the broadest interpretation of the appended claimsso as to encompass all such modifications as well as all relationshipsequivalent to those illustrated in the drawings and described in thespecification.

What is claimed as invention is:
 1. An STOL aircraft, comprising: afuselage having a port and a starboard side; at least one fixed wingcoupled to said fuselage and extending laterally from each of said portand said starboard side; at least one propeller coupled to either saidfuselage or said at least one fixed wing to provide thrust; a powerplant to power said at least one propeller; front and rear landing gearmodules operatively coupled to said fuselage, each of said front andrear landing gear modules including at least one rotatable landing gearstrut with a wheel disposed on its distal end, wherein said frontlanding gear module includes a port landing gear strut and a starboardlanding gear strut, each rotatingly coupled to said fuselage; landinggear motors for driving said front and said rear landing gear strutsindependently; and a control system for controlling said landing gearmotors to deploy and retract said front and rear landing gear struts;wherein said control system is configured to rotate one or more of saidlanding gear struts in response to aircraft flight condition andposition data, including airspeed, groundspeed, and position in relationto a runway; wherein said control system is programmed to drive said atleast one front landing gear strut downwardly during takeoff to increasethe aircraft angle of attack.
 2. An electrically powered STOL aircraft,comprising: a fuselage; fixed wings coupled to said fuselage; at leastthree electrically powered landing gear modules operatively coupled tosaid fuselage, each of said landing gear modules including a rotatablestrut having a wheel disposed on an outer end; an electric power supplydisposed in said fuselage; at least one propeller mounted on saidfuselage or on said wings; at least one power plant electrically coupledto said electric power supply to provide power to said at least onepropeller; an avionics control system for selectively deploying said atleast three landing gear modules, including deploying said front landinggear downward to induce rotation on takeoff and actively deploying oneor more of said landing gear modules downwardly to close the distance tothe runway on landing and retract after touchdown to absorb energy. 3.The aircraft of claim 2, wherein at least one of said landing gearstruts includes a driven wheel disposed on an outer end.
 4. The aircraftof claim 3, wherein at least one wheel of each of said front and rearlanding gear modules includes a driven wheel.
 5. The aircraft of claim2, wherein said avionics control system lowers at least one module ofsaid landing gear modules on landing in response to aircraft flightconditions and position in relation to a runway.